Effect of Decreasing the Force of Right Atrial Contraction on Right Ventricular Stroke Volume

Boyd, Daniel L.; Williams, John W

doi:10.1161/01.res.21.5.641

Cited by 4 publications

(2 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…From our study, we think that we could explain the indirect mechanical relationships between the right ventricular function and the right atrial dynamic contraction. From the physiological point of view, the contractile function of the atria has a strong relation to the thrombogenesis or thrombosis (Williams, et al, 1967;Wolf, et al, 1991;Lim, et al, 2013). Our focus and the data from this study suggested that the dynamics is one of the other factors to promote total flow dynamics in the pulmonary circulation as well as systemic circulation with the capability of elimination of stroke events.…”

Section: Discussionmentioning

confidence: 62%

Effect of right atrial contraction on prosthetic valve function in a mechanical pulmonary circulatory system

Tsuboko

Shiraishi

Matsuo

et al. 2016

JBSE

View full text Add to dashboard Cite

Improving the inflow characteristics of the right ventricular function and pulmonary circulatory hemodynamics was essential for more precise evaluation of newly designed heart valves. To examine a pulmonary hemodynamics, the authors have been developing a pulmonary mechanical mock circulatory system. In this study, the pneumatically driven right atrium model was newly developed for clarifying the effect of atrial contraction on the dynamic behavior of pulmonary prosthetic valves. We focused on the hemodynamic behavior of the outflow mechanical heart valve of the right ventricle that could be affected by the right atrial dynamic motion. A medical-grade bileaflet valve was employed and installed into the outflow portion of the right ventricle model and examined its changes in hemodynamic behavior caused by the active right atrial contraction. With the active atrial contraction, hemodynamic waveforms of either the right ventricle or atrium were obtained using the modified pulmonary mock circulatory system. The characteristics with atrial contraction were well simulated as the natural hemodynamics. The right ventricular output increased by around 5% and the peak regurgitant flow at the moment of valve closing significantly decreased by the presence of the atrial contraction. Our mechanical circulatory system could simulate the end-diastolic right ventricular inflow characteristics. We found that the atrial contraction under the low pressure condition such as pulmonary circulation promoted earlier valve closing and prolonged closing duration of prosthetic valve. The simulation of right atrial contraction was important in the quantitative examination of right heart prosthetic valves for congenital heart malformation.

show abstract

Section: Discussionmentioning

confidence: 62%

Effect of right atrial contraction on prosthetic valve function in a mechanical pulmonary circulatory system

Tsuboko

Shiraishi

Matsuo

et al. 2016

JBSE

View full text Add to dashboard Cite

show abstract

“…Nevertheless, the RA pressure tracing in all TI dogs were characteristic of tricuspid insufficiency. Mean right ventricular pressure in TI dogs (mean systolic = 43 ± 1.2 mm Hg, n = 7) was slightly higher than in open-chest, chlorolose-anesthetized dogs (RV systolic pressure = 20 mm; range 16-42 mm Hg) as reported by Boyd and Williams (1967).…”

Section: Right Atrial Pressurementioning

confidence: 53%

The effects on atrial electrophysiology and structure of surgically induced right atrial enlargement in dogs.

Boyden¹,

Hoffman²

1981

Circulation Research

130

View full text Add to dashboard Cite

We evaluated the relationship between susceptibility to arrhythmias caused by right atrial (RA) enlargement and alterations in transmembrane potentials and ultrastructure. RA enlargement was produced in eight dogs (TI) by excising the septal cusp of the tricuspid valve through a right atriotomy and constricting the pulmonary artery. This procedure resulted in RA dilation and hypertrophy. Four sham-operated dogs (S) also were studied. Neither TI nor S dogs developed spontaneous atrial arrhythmias. Atrial overdrive (OD) and premature stimulation (PS) were used to initiate and terminate arrhythmias. At 2 weeks and for 20 to 30 weeks after surgical preparation, TI dogs were more susceptible to arrhythmias than S dogs. The duration of arrhythmias exceeded 10 minutes more often in TI dogs than in S dogs. Sixty-one percent of all arrhythmias in the TI dogs had rates of 320-450 impulses/min, and electrogram and ECG characteristics of atrial flutter (type II rhythm), whereas no S dogs developed rhythms with these slower rates. The type II rhythms were persistent, 30% lasting longer than 30 minutes, while 22% lasted more than 60 minutes. Transmembrane potentials recorded in vitro from the RA free wall of TI dogs, and responses to norepinephrine and acetylcholine were not different from control. Histological and ultrastructural studies on TI atria showed hypertrophy of fibers and some increase in connective tissue between cells. These results suggests that altered susceptibility to long-lasting arrhythmias need not be associated with significant abnormalities of cellular electrophysiology.

show abstract

Politische Symbolik der UNO und symbolische Vereinte Nationen

Wesel¹

2004

Symbolische Politik Der Vereinten Nationen

View full text Add to dashboard Cite

Effect of Decreasing the Force of Right Atrial Contraction on Right Ventricular Stroke Volume

Cited by 4 publications

References 24 publications

Effect of right atrial contraction on prosthetic valve function in a mechanical pulmonary circulatory system

Effect of right atrial contraction on prosthetic valve function in a mechanical pulmonary circulatory system

The effects on atrial electrophysiology and structure of surgically induced right atrial enlargement in dogs.

Politische Symbolik der UNO und symbolische Vereinte Nationen

Contact Info

Product

Resources

About